Date : 16/10/2023

Relevance: GS Paper 3- Environment - Global Warming and Climate Change

Keywords: Himalayan glaciers, Aerosol radiative forcing, Hindu Kush-Himalaya-Tibetan Plateau, Cryosphere impact, Glacial Lake Outburst Floods

Context-

• Indian Space Research Organization (ISRO) and the Research Institute for Sustainability have revealed that the Hindu Kush–Himalaya–Tibetan Plateau is experiencing significant warming, with aerosols playing a crucial role in this process.
• They found that aerosol levels over the Terai regions of the Himalayas and the Ganges Plains have increased, while the concentration of pollutants at higher altitudes is also rising.

Aerosols' Significant Role:

• The report indicates that aerosols are responsible for heating the lower atmosphere in the Hindu Kush Himalaya and Tibetan Plateau regions, which is a major factor in climate change.
• The study, the first of its kind, used ground-based observations, satellite data, and simulations, to assess aerosol characteristics and radiative forcing the change in energy flux in the atmosphere caused by natural or anthropogenic factors of climate in several locations in the Indo-Gangetic Plains (IGP), the Himalayan foothills and the Tibetan Plateau.
• Data shows that the aerosol radiative forcing efficiency (ARFE) which shows the effect of anthropogenic aerosols on the radiative fluxes at the top of the atmosphere was significantly higher in the Himalayan foothills.
• “The mean ARFE is two to four times higher here than over other polluted sites in south and east Asia, owing to higher AOD (aerosol optical depth) and aerosol absorption. Further, the observed annual mean aerosol-induced atmospheric heating rates (0.5–0.8 Kelvin/day), which are significantly higher than previously reported values for the region, imply that the aerosols alone could account for over 50% of the total warming, including aerosols and greenhouse gases, of the lower atmosphere and surface over this region
• Notably, aerosols are not only causing the region to warm up but also significantly affecting the melting rate of glaciers and altering precipitation patterns.

Impact on Asia's Population:

• Hindu Kush–Himalaya–Tibetan Plateau is the world's largest mountain range, stretching from Afghanistan to Myanmar and including countries such as India, Pakistan, Nepal, Bhutan, China, and Bangladesh. It serves as a direct or indirect source of water for nearly 2 billion people, as the rivers originating from its glaciers fulfill their water needs.
• The Hindu Kush-Himalaya-Tibetan Plateau region contains the largest ice mass outside the Antarctic and Arctic polar regions and has witnessed a pronounced retreat in glaciers, which also feed into most major rivers of Asia.
• The warming of the Himalayas has direct implications for the approximately 2 billion people in Asia who rely on the region not only for drinking water but also for irrigation and energy. The study emphasizes that the situation is more critical than previously thought, and its effects are already evident in the monsoon patterns of Asia.

Consequences of Warming Himalayas:

International Centre for Integrated Mountain Development (ICIMOD)'s report 2019:

• It found that the Hindu-Kush Himalayas are warming faster than the global average and It highlighted that 1.5 degrees Celsius is “too hot” for the Himalayas region and consequences will be severe.
• David Molden, former director-general of ICIMOD, said that global warming of 1.5 degrees Celsius will actually mean a 2 degrees Celsius temperature increase in the mountains
• The rising temperatures in the Himalayas are destabilizing glaciers, posing a threat to areas inhabited by vulnerable communities, and increasing the risk of events like landslides. The rapid melting of glaciers contributes to untimely flooding, becoming a secondary driver for natural disasters.

Earlier reports (impact on Cryosphere):

• Earlier reports have highlighted the severe impact of climate change on the cryosphere, which includes areas on Earth covered by snow and ice. Mt. Everest's glaciers, for example, have lost 2,000 years' worth of ice in just the past 30 years.
• For the first time, these studies map the connections between changes in the cryosphere and their consequences for water resources, ecosystems, and society in the mountain region. Key findings from the reports reveal that Himalayan glaciers have been disappearing 65 percent faster since 2010 compared to the previous decade. This accelerated loss of snow and ice due to global warming will lead to reduced freshwater availability for downstream populations.
• Additionally, the study identifies around 200 glacier lakes in the region as dangerous, potentially resulting in a significant increase in glacial lake outburst floods by the end of the century.
• The report emphasizes that communities in the mountain regions are suffering the impacts of climate change more profoundly than many other parts of the world. The changes in glaciers, snow, and permafrost in the Hindu Kush Himalayan region are described as "unprecedented and largely irreversible."
• Some Himalayan communities are already experiencing the effects of climate change, such as the sinking of the Indian mountain town of Joshimath earlier this year, which necessitated the relocation of residents. A Glacial Lake Outburst Flood (GLOF) occurred in Sikkim, and in February 2021, Chamoli district in Uttarakhand witnessed flash floods believed to be potentially triggered by GLOFs.
• The International Cryosphere Climate Initiative, emphasized the difficulty of restoring ice once it has melted, likening it to a large ship in the ocean that is challenging to halt once it starts moving. It stressed the importance of limiting global warming to the 1.5 degrees Celsius target agreed upon in the 2015 Paris Climate Conference, as irreversible changes are already underway in the cryosphere.
• Despite efforts to limit warming to the 1.5 to 2 degrees Celsius range from pre-industrial levels as set out in the Paris climate treaty, the report predicts that glaciers are likely to lose a significant portion of their volume by 2100.

Government Initiatives Related to Protecting the Himalayan Region

• National Mission on Sustaining Himalayan Ecosystem (NMSHE): Launched in 2010, NMSHE is part of India's National Action Plan on Climate Change, addressing climate challenges in the Himalayan region. Covering 11 states and 2 Union Territories, it focuses on sustainable development and conservation, safeguarding the Himalayan ecosystem.
• SECURE Himalaya Project: Funded by the Global Environment Facility (GEF), the SECURE Himalaya Project is part of a global effort to conserve wildlife and combat environmental crimes in the Himalayas. It promotes sustainable management of alpine ecosystems, benefiting biodiversity and local communities.
• Mishra Committee Report 1976: The Mishra Committee Report, named after MC Mishra, investigated land subsidence in Joshimath, a Himalayan town. It recommended restrictions on construction, blasting, and tree felling to address the issue, influencing responsible land use in the region.

What Other Measures Can Be Taken to Protect the Himalayan Ecosystem?

• Emphasis on Paris Pact and Other Global Initiatives: The Paris Pact functions as an essential bridge between political commitment at the highest international levels and the prioritization of technical assistance interventions on the ground
• Trans-Boundary Collaboration: Himalayan nations must establish an international network dedicated to monitoring and providing early warnings for risks like those stemming from glacial lakes. This network, akin to the Indian Ocean tsunami warning systems developed over the past decade, should facilitate knowledge-sharing and ecological preservation efforts across borders.
• Education and Awareness: A heightened level of awareness among Himalayan residents regarding their region's geological vulnerability and ecological delicacy would likely drive greater adherence to environmental regulations. It is imperative that India and other affected countries incorporate fundamental knowledge about Himalayan geology and ecology into their educational curricula
• Local Government Initiatives: Municipalities in Himalayan states should adopt a more proactive stance when granting construction approvals, with building regulations adapting to address the emerging challenges of climate change. Additionally, disaster management departments should pivot their strategies toward flood prevention and preparedness.

Conclusion

The study highlights the critical role of aerosols in accelerating the warming of the Himalayas, with far-reaching consequences for both the region and the millions of people who depend on its water resources.

Furthermore, the aerosols are causing significant damage to glaciers in the 2,000-kilometer-long Himalayan mountain range, which will ultimately affect the region's hydrological cycle, leading to changes in precipitation patterns and the impact of monsoons. This will have profound implications for India and the surrounding regions.

The findings suggest that the situation is even more precarious than previously believed, and urgent action is needed to address the challenges posed by climate change in this vital part of the world.

Source- The Hindustan Times/ News 18/ PIB